Change the include path in examples as #175 (#180)

* Change the include path in examples as #175

* Change include path in scripts
diff --git a/examples/all_features/subcases.cpp b/examples/all_features/subcases.cpp
index 50e8590..e20a296 100644
--- a/examples/all_features/subcases.cpp
+++ b/examples/all_features/subcases.cpp
@@ -1,4 +1,4 @@
-#include "doctest.h"
+#include <doctest/doctest.h>
 
 #include "header.h"